ASP.NET - ASP.NET錯誤日誌寫入

當我們一個web項目開發已完成，測試也通過了後，就把他放到網上去，但是，bug是測不完的，特別是在一個大的網絡環境下。那麼，我們就應該記錄這些錯誤，然後改正。這裏，我的出錯管理頁面是在global.asax裏面的，因爲裏面有一個Application_Error函數，我覺得這個就是管理錯誤的。其實，asp.net裏還有一個方法，就是在 page 裏指定出錯的頁面，由這個頁面專門管理，我覺得這個方法也好，但是每次都要到相應的page裏指定參數，不過，我覺得應該可以在web.config裏配置吧。但是我還是喜歡下面的方法。下面我們就開始吧。
Global.asax代碼：

<%@ Application Language="C#" %>

<script runat="server">

        void Application_Start(object sender, EventArgs e)    
        {
                // 在應用程序啓動時運行的代碼

        }
        
        void Application_End(object sender, EventArgs e)    
        {
                //    在應用程序關閉時運行的代碼

        }
                
        void Application_Error(object sender, EventArgs e)    
        {    
                // 在出現未處理的錯誤時運行的代碼
                
                        Exception objErr = Server.GetLastError().GetBaseException();
                        string error = string.Empty;
                        string errortime = string.Empty;
                        string erroraddr = string.Empty;
                        string errorinfo = string.Empty;
                        string errorsource = string.Empty;
                        string errortrace = string.Empty;

                        error += "發生時間:" + System.DateTime.Now.ToString() + "<br>";
                        errortime = "發生時間:" + System.DateTime.Now.ToString();

                        error += "發生異常頁: " + Request.Url.ToString() + "<br>";
                        erroraddr = "發生異常頁: " + Request.Url.ToString();

                        error += "異常信息: " + objErr.Message + "<br>";
                        errorinfo = "異常信息: " + objErr.Message;

                        //error +="錯誤源:"+objErr.Source+"<br>";
                        //error += "堆棧信息:" + objErr.StackTrace + "<br>";
                        errorsource = "錯誤源:" + objErr.Source;
                        errortrace = "堆棧信息:" + objErr.StackTrace;
                        error += "--------------------------------------<br>";
                        Server.ClearError();
                        Application["error"] = error;

                        //獨佔方式，因爲文件只能由一個進程寫入.
                     System.IO.StreamWriter writer=null;
                        try
                        {                                
                                lock (this)
                                {
                                        // 寫入日誌
                                        string year = DateTime.Now.Year.ToString();
                                        string month = DateTime.Now.Month.ToString();
                                        string path = string.Empty;
                                        string filename = DateTime.Now.Day.ToString() + ".txt";
                                        path = Server.MapPath("~/Error/") + year + "/" + month;
                                        //如果目錄不存在則創建
                                        if (!System.IO.Directory.Exists(path))
                                        {
                                                System.IO.Directory.CreateDirectory(path);
                                        }
                                        System.IO.FileInfo file = new System.IO.FileInfo(path + "/" + filename);
                                        //if (!file.Exists)
                                        //        file.Create();
                                        //file.Open(System.IO.FileMode.Append);                
                                        writer = new System.IO.StreamWriter(file.FullName, true);//文件不存在就創建,true表示追加
                                        writer.WriteLine("用戶IP:" + Request.UserHostAddress);
                                        //if (Session["UserName"] != null)
                                        //{
                                        //        writer.WriteLine("用戶名" + System.Web.HttpContext.Current.Session["UserName"].ToString());
                                        //}
                                        writer.WriteLine(errortime);
                                        writer.WriteLine(erroraddr);
                                        writer.WriteLine(errorinfo);
                                        writer.WriteLine(errorsource);
                                        writer.WriteLine(errortrace);
                                        writer.WriteLine("--------------------------------------------------------------------------------------");
                                        //writer.Close();
                                }
                        }
                        finally    
                        {
                                if (writer != null)
                                        writer.Close();
                                        
                        }        
                        Response.Redirect("~/Error/ErrorPage.aspx");
                

        }

        void Session_Start(object sender, EventArgs e)    
        {
                // 在新會話啓動時運行的代碼
                Session.Timeout = 60;                
                if (Session.IsNewSession)
                {
                        lock (this)
                        {
                                if (Application["Counts"] != null)
                                {
                                        Application["Counts"] = Int32.Parse(Application["Counts"].ToString()) + 1;
                                }
                                else
                                {
                                        Application["Counts"] = 1;
                                }
                        }
                }
        }

        void Session_End(object sender, EventArgs e)    
        {
                // 在會話結束時運行的代碼。    
                // 注意: 只有在 Web.config 文件中的 sessionstate 模式設置爲
                // InProc 時，纔會引發 Session_End 事件。如果會話模式設置爲 StateServer    
                // 或 SQLServer，則不會引發該事件。
                if (Application["Counts"] != null)
                {
                        Application["Counts"] = Int32.Parse(Application["Counts"].ToString())-1;
                }                
        }
                
</script>

顯示出錯信息的頁面
ErrorPage.aspx代碼:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ErrorPage.aspx.cs" Inherits="Error_ErrorPage" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
        <title>出錯信息</title>
        <link href="css/SITE.CSS" type="text/css" rel="stylesheet" />        
</head>
<body>
        <form id="form1" runat="server">
                <asp:Label ID="Label1" runat="server" Width="568px"></asp:Label>
        
        </form>
</body>
</html>

ErrorPage.aspx.cs

protected void Page_Load(object sender, EventArgs e)
        {
                this.Label1.Text = Application["Error"].ToString();
        }